Fibertex geosynthetics solutions encompass Controlled Permeability Formwork (CPF) liners, designed for concrete surface enhancement in diverse applications, including highly aggressive environments.
Typical applications of Fibertex Formtex® CPF liners are in potable water tanks, wastewater treatment plants, settlement tanks, container terminals, bridges and tunnels, marine structures, as well as dams and sluices.
“The main functions of Formtex® CPF liners are to improve the durability of a concrete structure, to extend its service life and reduce maintenance costs,” says Brian Potgieter, Technical Sales Engineer, Fibertex South Africa. Degradation of concrete structures is normally accelerated by the effects of salt water, high temperatures and increased CO2 levels in the air.
“Formtex is a two-layer CPF liner, consisting of a drainage layer that allows water and air to escape and a filter layer with a pore size designed to retain cement particles. When surplus water and air is drained from the surface of the freshly poured concrete during compaction, the water/cement (w/c) ratio in the concrete cover is reduced. This results in a denser and stronger concrete, with a blemish-free surface.”
Formtex CPF liners, which are suitable for the rounded shape of concrete elements, are used in the casting of bridge pillars and bridge spans, to ensure high quality, durability and low maintenance of the concrete elements that need to withstand aggressive environments.
Formtex also reduces the formation of blowholes and other blemishes on the concrete surface that normally require extensive deburring after the formwork is removed. The smooth, dense and strong concrete cover is dust-free and because there are no release agents, it is an ideal prepared base for further surface treatment or coatings.
Formtex CPF liners, which reduce micro bacterial growth, are an efficient alternative to slip agents for fresh water supply structures. CPF liners also minimise the penetration of graffiti media, making it easy to remove from a surface.
The chemical and mechanical resistance of concrete structures of sewage plants and settlement tanks are important factors for consideration. The concrete face, which is in constant contact with wastewater, needs to withstand the penetration of aggressive substances and high-pressure cleaning procedures.
In potable water tanks, mechanical resistance of the concrete is also imperative, as the concrete face is subjected to high-pressure cleaning and, because micro-organisms flourish in voids and feed on oils, it is critical that the concrete surface is smooth, uncontaminated and free from blowholes.
Formtex is designed for tensioned, glued or self-adhesive mounting to vertical or inclined surfaces. Once Formtex is attached, concrete casting is performed as usual. These liners can easily be removed from the concrete during formwork striking.
The Fibertex geosynthetics range encompasses nonwoven and woven geotextiles, gabions and mattresses, drainage pipes and fittings and erosion control and cellular confinement solutions. The company also supplies soil reinforcing and stabilising products, including geogrids and geocells, as well as geosynthetic clay liners as part of composite lining systems in modern landfills.
Fibertex is the largest manufacturer of UV stabilised virgin PP (polypropylene) nonwoven geotextiles produced in Africa, with certification for durability of over 100 years, in accordance with the latest EN standards.